Top 10 Saddest Songs from Cartoons

The most heartbreaking songs from animated TV shows, excluding anime, animated movies (Disney, Pixar, DreamWorks, etc.), theme songs, and background tracks I could think of.

Suggestions are always welcome.

The Top Ten

Leaves from the Vine - Avatar: The Last Airbender

Why It's Sad:
In the episode "Tales of Ba Sing Se," Iroh spends his whole day helping everyone around him, such as singing this song to calm a crying boy at the market place. At the end of his day, he sings this song in remembrance of his son Lu Ten, who died during the siege of Ba Sing Se while Iroh was still a Fire Nation general. Before he starts singing the war ballad, he says: "Happy birthday, my son. If only I could have helped you." He softly begins to cry, which makes the whole scene even more heart-breaking by stressing that Iroh has been helpful to every person in the episode but was not able to save his son. It shows that the loss of his son was what caused his change of heart regarding the war and made him the lovable character as we got to know him.
Lyrics:
Leaves from the vine
Falling so slow
Like fragile, tiny shells
Drifting in the foam
Little soldier boy
Come marching home
Brave soldier boy
Comes marching home
Gary Come Home - SpongeBob SquarePants

I think there are lots of sad songs in SpongeBob, but I believe this song really makes some people sad from the emotions SpongeBob shares, and some people sharing a connection about a loss of their dog or a lost dog which makes the song even more touching.

God, this was tearjerking. Seeing how crushed SpongeBob was made me cry.

I think the song from Dumped is sadder. I don't know why, but this is still really sad.
Remember You - Adventure Time

Why It's Sad:
Marceline sings this song together with the Ice King in the episode "I Remember You." It is revealed that before Simon became the mad Ice King, he took care of a crying Marceline after the Mushroom War. Marceline reads an old note from him to him, desperately trying to get her old friend to remember. But his memory remains lost.
Lyrics:
Marceline:
Marceline, is it just you and me in the wreckage of the world?
That must be so confusing for a little girl.
And I know you're going to need me here with you.
But I'm losing myself, and I'm afraid you're gonna lose me too.
This magic keeps me alive, but it's making me crazy,
And I need to save you, but who's going to save me?
Please forgive me for whatever I do,
When I don't remember you.
Ice King:
Marceline, I can feel myself slipping away.
I can't remember what it made me say.
But I remember that I saw you frown.
I swear it wasn't me, it was the crown.
Together:
This magic keeps me alive, but it's making me crazy.
And I need to save you, but who's going to save me?
Please forgive me for whatever I do,
When I don't remember you.
Please forgive me for whatever I do,
When I don't remember you.
Hero Song - The Amazing World of Gumball

I've never cried from anything fictional, but this got me really close.
It's Over, Isn't It - Steven Universe
Everything Stays - Adventure Time

One of the best moments in the series, pure love between mother and daughter.
A Grill Is Not a Home - SpongeBob SquarePants
What Might Have Been - Phineas and Ferb

This is sad. Isabella and Phineas not being together and feeling like it's too late.
Remember - Danny Phantom
When She Loved Me - Toy Story 2

The Newcomers

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I Used to Be Her Favorite - Big Mouth
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Start Over - Clone High

This is the song that played during the last episode of Clone High for over 20 years, when the clones at prom get frozen.

The Contenders

I Will Go Sailing No More - Toy Story
My Little Ones - The Amazing World of Gumball
Oh My Izzy - Total Drama

Very underrated sad song. Yes, I know a breakup is not as sad as the other songs but come on! This would be a good number 8. It's mostly the music that boosts it.

Ohh Izzy
Ohh Izzy
Why'd you leave me so?
Oh my Izzy
My little Izzy
Why'd I ever let you go?

Even though the lyrics of the verses are somewhat funny, the chorus is what hits you hard.
What's the Use of Feeling Blue - Steven Universe

Steven Universe has the saddest songs.
Drift Away - Steven Universe

When Spinel got left at the garden, it broke my heart.
Karla's Lullaby - We Bare Bears
The Pony I Want to Be - My Little Pony: Friendship Is Magic
I've Got to Find a Way - My Little Pony: Friendship Is Magic
I Have Time - We Bare Bears
Young Lemonhope - Adventure Time

This is way sadder than Remember You.
This Big World - Winx Club

It's the song Musa sings to her dead mother.
Full Disclosure - Steven Universe
Potatoes and Molasses (Reprise) - Over the Garden Wall
I Will Wait for You - Futurama

The song was sad because Seymour had to wait for Fry all day long.

This episode is from Jurassic Bark.
When I Was His Alien - American Dad!

In the episode "A.T. The Abusive Terrestrial," Steve does not want to spend more time with his best friend Roger. However, Roger wanted to maintain his friendship with him, so he decided to meet Henry, who lived in his house, and Roger wanted to stay with him for a while.